1. Field of the Invention
The invention relates in general to equipment for interconnecting color television signals between a broadband network BN and video sources VQ and video using equipment VK which are connected thereto and in particular to an improved switching system for video signals.
2. Description of the Prior Art
Various video sources and various video user equipment or sinks must be connected to a broadband network. The video sources should also be interconnectible with a video using equipment or sinks of a user. In this application, video sources may, for example, be sources of video signals such as a video camera, a video recorder, a television tuner or a video disk playback unit. In this application, television using equipment or video sinks comprise television receivers, monitors, video recorders or video hard copying machines which are examples of video sinks. It is desired that all video sources are capable of being connected to all video sinks and, of course, also being connectible to the broadband network and for this requirement it is necessary to employ uniformly coded color television signals. For qualitative reasons, only a television signal divided into components need be considered. It has previously been known to through-connect the components of a video signal between video sources and video sinks and to the broadband network using a switching matrix network comprising a plurality of switching levels. High qualitative demands are made of the switching matrix network so as to satisfactorily solve the cross-talk problem. A simple CMOS switch is thus not satisfactory for a cross-point. The "Video-Handbuch" by Ru van Wezel, FranzisVerlag Munich 1977 discloses a cross-point of a cross-bar distributor on page 124. A correspondingly constructed switching matrix network would require a large monetary outlay due to the large number of levels required.